Brake



Nov. 13, 1934. c. BRISSON 1 ,980,611

BRAKE Filed Oct, 28, 1932 4 Sheets-Sheet l 1934- L. c. BRISSON 1,980,611

BRAKE Filed 001:. 28. 1932 4 Sheets-Sheet 2 fig. a.

I Nov. 13, 1934.

L. C. BRISSON BRAKE Filed Oct. 28, 1932 4 Sheets-Sheet 3 j 8, El /55mNov. 13,1934. L. c. BRISSON 1,980,611

BRAKE Filed Go t/28, 1952 4 Sheets-Sheet 4 Patented Nov. 13,1934

PATENT OFFICE BRAKE Louis Charles Brisson,

Boulog'ne-su'r-Seine,

France, assignor to Socit Anonyme: Socit des Freins Hydrauliques S. deLavaud, Paris,

France Application October 28,

1932, Serial No.' 640,098

In France November 3, 1931 4 Claims.

In hydraulically controlled brakes, it is a recognized fact that thedevice receiving the hydraulic pressure should be arranged outside thefixed cheek member, so that it should not be sub- 5 jected to the heatevolved within the brake drum. Consequently, it was necessary to providea stress transmitting device between the plunger of the device receivingthe hydraulic pressure and the brake jaws.

A device has already been proposed which consists in a parallel motionthe jointsof2 which serve as axes for bearing rollers. One of theserollers is in contact with the driving plunger, and the opposite rollerbears against a fixed surface. The two other rollers respectively bearagainst both receiving plungers.

This proposed device has inconveniences, particularly when it is usedfor actuating the brakes of any vehicle, and especially self-applyingbrakes.

In this specification, in order to define the ends of the brake jaws andthe plunger which respectively correspond to said ends, reference willbe made to the direction of rotation of the brake drum. By starting fromthe actuating device, and by moving 'in'the direction of rotation of thedrum, the first plunger and the first jaw encountered will be designatedby the terms first plunger and "first jaw", whilst the last jaw and thelast plunger encountered will be designated by the terms last plungerand last jaw.

It will be understood that, in this application (and for instance whenthe brakes are applied during forward running) the roller bearingagainst the last plunger (that on which bears the last jaw) remainsstationary, as well moreover as the roller bearing against the fixedwall. In these conditions, the axis of the roller bearing against thedriving plunger moves according to 4.0 an arc of circle which greatlydeparts from the straight line according to which the piston moves,because the adjacent side of the parallel motion forms, with thisstraight line,'an angle very different from 90. The same is true for theplunger bearing against the first plunger.

Consequently, a friction is produced between the driving plunger and itsroller, on the one hand, and between the first plunger and its roller,on the other hand, which friction canbe considerable. In fact, thediameter of the rollers cannot be verylarge and very different from thatof their spindles, owing to cumbersomeness. The rolling friction takingplace is not therefore very different from the sliding friction whichwouldoccur if the rollers were fast on their spindles;

this parasitic friction is extremely prejudicious to proper balancing ofthe brakes, as it often happens that it is very different for the two110- mologous wheels (for instance the front wheels), The consequencesof this unbalancing are more particularly to be feared if it isconsidered that the inclination of the sides of the parallel motion onthe axes on which the plung'ers' move progressively increase towards 90for the parallel motion first actuated, that is to say for that havingthe least friction. This increase of inclination has for efiect, on theone hand, to further diminish this friction and, on the other hand, toincrease the transmission from a higher to a lower speed produced by theparallel motion, this consequently accentuating unbalancing in proportion as the brakes are applied. v

The main object of the present invention is to avoid theseinconveniences, and for that purpose, to impart to'fthe rollers (atleast in the direction of forward running) a movement differing asslightly as possible from that of the plunger with which they come incontact. v

It is mainly characterized by the fact that the spindle of therollerassociated with the driving plunger and that ,of the rollerassociated with the plunger first encountered when running forwardaremounted on a lever pivoted on a'sl pport bearing, on the one hand, onthe plunger last encountered when. running forward, and, on the otherhand, on a fixed surface, and by the fact that the pivoting axis of thelever is situated at the intersection of two planes extending throughthe axes of the rcllersin their initial position and forming, with thedirections of movement.

" of the pistons associated therewith, an angle approximating 90. I

This angle will differ to the extent of 90 from one half the maximumangular displacement of thelever.

This invention can be carried out according to various forms ofconstruction, particularly differing from each other by theconstitution, of the support which, for reverse drive, plays an activepart and, must therefore, in this case,ftransmit to the first plunger(that is to say the piston first encountered' when running forward)- thethrust of the driving plunger. The following forms of construction canthus be considered: 7

(a) The support is constituted. by a carriage provided with rollersrunning on fixed raceways preferably displaced relatively to each:other,

(b) The support is constituted by a lever pivoted about a fixed axis andon which is pivoted, Q t e same axis as the lever carrying the actuatingrollers, an arm, the free end of which extends in a corresponding recessprovided in the last plunger (forward running).

The support is pivoted about a fixed axis I and comprises an armbearing'in a corresponding recess provided in the lastpiston (forwardrunning), this arm being pivoted on the support about an axis diiferent'from that of the lever carrying the rollers.

10 The invention also relates, to other particular points which willappear from the following description with reference to the accompanyingdrawingaglven by way of example only, and in ll Fig.1 is an elevation,in section, of a first form of construction. Fig. 2 is a correspondingplan view.

. 8 is a section III-III of Fig. 1. .0 Fig. 4 is an elevation, in axialsection, of a second form of construction.

' Fig. 5 is a plan view corresponding to the preceding figure.

Fig. 6 is a section made according to line VI-VI 85 of Fig. 4.

Fig. '7 is an elevation, in axial section, of a third v described(whenapply'ing the brakesv during forform of construction.

Fig. 8 is a section made. according, to linei0 .1 18. 9 is a sectionalview partly inelevation showing the device'applied to brake shoes.

In the various figures of the drawings, the same parts are designated bythe same reference numbersg w g The forms oi' construction illustratedwhich are more particularly applicable to bydraulic brakes mounted onmotorfvehicles, comprise a driving plunger 1 and two receiving pis--tone 2 and 3, the. piston 3 being the plunger .flrst 40 encountered whenrunning forward. I The cylinders for the plungers 2 and 3 are providedin one and the same casting 4 within which a member 6 is securedthroughthe. medium of any suitable means, such asfscrews 5.

The leveron whichthe rollers I and 8 are iour-l nailed, which rollersrespectively cooperate with the driving plunger 1 and the receivingpiston 3. isindicatedat9. v

In the first form of construction illustrated in I I0 .l 'lgs. 1, 2 and3, the lever 9 on which the rollers H and 8 are journalled, isconstituted by two cheek members pivoted about a pivot 10. Y

' It will be noted that, according to the invenk tion, the straightlines 10 -11 and '10-12 (11 and B5 12 .,being respectively the axes ofthe rollers '7 and 8) form, with the, straight lines 02! and CY,

angles approximating 90, asindicated in the features of the presentpatentapplication.

The pivot or pin 10 is rigid-with a, carriage 13 9 v flvlded withrollers 14 and 15 running on raceways 16 and 17 displaced relatively toeach other,

a but parallel andprovided on the member 6.

; When applying the brakes during forward run- ;ning, the plunger 1moves from x towards 0, to the roller '1 and. consequently, angularlymoving the lever 9 about the pin 10. In

ignated by the same reference numbers. In this i made according to linedifferent (particularly, concerning ,the spindle. 1 1

. place to cause unbalancing'ofthe system: Braking duri 1 reverserunning I (second form spectively, according to which the plungersl and3 move. I

Figs. 4, 5 and 6 illustrate a, second form of construction in which thesame parts are desform of construction the support is constituted by thecombination of two links 20 and 21 pivoted aboutthe common pin 10 of thelever'9. 'I'he 1m: 20 is pivoted about a fixed pin 22 mounted V in themember 6 andthe free end of the link 21 bears'in a recess 23'axiallyprovided in; the .j

that previously indicated, the free endof the lever 21 bearing (whenapplying the brakes durlng forward running) on theplunger 2, and thedisplacement of the lever '9.- v Eigs. 7 and 8 illustrate a third formof construbtion in which the support is constituted by two cheek memberspivoted about a spindle I 22 rigid with the member 6 and bears on theplunger "2, in a recess 23 provided in the latter, through the medium ofan arm 31 pivoted at 32 on a Support 30. v t

The operation is identical to that previously plunger 3 is moved from 0towards Y by angular.

ward running). 7 v I In the various forms of construction fillustrated,the plunger 1 can be driven by'anys'uit-v able means (mechanical,electrical, hydraulic'or like means) For efiecting braking duringreverse'running,

The roller8 bears on the plunger-,3 I.

the angular movement of the lever 9' causes the displacement, in thedirection of the arrow F1, of the support or carriage 13 and,consequently,

of the plunger 2. Duringreverserunning, the

displacements of theroll'er spindles are distinctly of roller '1) fromth'e'displaceinents of the pistons. Braking during reverse running .issubstantially eflected during. relatively short ,periods of time whichdo not allow the} sliding frictions taking:

of construction).

In this case, the arm angular-1y moves" about I the spindle 22in thedirection ofthea'rro'wIll:

and acts on the plunger .2 through the rnediuin w Braking during ofconstruction). I if I The operation is identicahto that for the second.form of construction.

It is obvious that the invention is not. limited to the forms ofconstruction described andillustrated, but that it includes thoseutilizing'identical means in order to obtain thebalancingof v a the.system, asindic'ated. g Y 1 I What I claim as my invention anddesire tosecure by Letters Patent is: a I

1. In a device for transmitting stresses to Y brake law's, a fixedframe, two opposite movable receiving plungers having one and the samegeo- 146 metrical axis. a driving plungerso arranged that v itsgeometrical axis is perpendicular to the preceding one, a bent lever,means for supporting the said lever in such a manner thatone'of its insuch a manner that one of the rollers is in contact with the drivingplunger and the other with one of the receiving plungers, the said "supportingmeans being operatively the other plunger.

3. In a device for transmitting stresses to brake Jaws, a fixed frame,two opposite movable receiving plungers having one and the samegeometrical axis, a driving plunger so arranged that itsgeometrical axisis perpendicular to the pres ceding one, a lever, rollers pivoted ateach end associated with t "8 ofthesaidievenmeansforarpportipgthislcverin such a manner thatlone of the rollers is in contact with the drivingplunger and the other with one of the receiving plungers, the said meanscomprising a link, connectingthepivot of the.

lever to a fix'ed joint, and another link connecting the said pivot-tothe second receiving plunger.

'4.In a device for'transmitting brake'jaws, a nxedframe, opposite-mowable receiving plungers having one and the same geometrical axis,adrivingplunger 'so arranged I I that its geometrical axis is.perpendicular to the preceding one, a lever, rollers pivoted at mu endof the saidzlever, means for supporting this lever in such a mannerthatjone-of the rollers is in contact with the driving plunger and theother with one of the, receiving ,plungers, the said means comprising amember pivoted on the fixed frame and connected by a link to thereceiving plunger.

at mmscmnnmnarsson.

